title: Life-threatening diphenhydramine toxicity presenting with seizures and a wide complex tachycardia improved with intravenous fat emulsion.
abstract: Diphenhydramine toxicity manifests with signs of anticholinergic toxicity; therapy is generally supportive. In rare cases, patients can also present with a wide complex tachycardia due to sodium channel blockade. Treatment involves sodium bicarbonate. Lidocaine and hypertonic saline are used for arrhythmias refractory to sodium bicarbonate. Although intravenous fat emulsion (IFE) therapy is proposed as an adjunctive therapy due to the lipophilicity of diphenhydramine (octanol/water partition coefficient of 3.3), successful use of IFE after a confirmed sole ingestion of diphenhydramine is not previously reported. We present the case of a 30-year-old woman presenting with seizures, a wide complex tachycardia, and cardiovascular collapse after an ingestion of diphenhydramine refractory to other therapies with rapid improvement after IFE administration.
authors.affiliation: 1Barnes-Jewish Hospital, Division of Emergency Medicine, St Louis, MO; 2Division of Emergency Medicine, Washington University School of Medicine, St Louis, MO; and Barnes-Jewish Hospital, Department of Pharmacy, St Louis, MO.
authors.forename: Dimyana
authors.initials: D
authors.lastname: Abdelmalek
authors.forename: Evan S
authors.initials: ES
authors.lastname: Schwarz
authors.forename: Christopher
authors.initials: C
authors.lastname: Sampson
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Halcomb
authors.forename: Craig
authors.initials: C
authors.lastname: McCammon
authors.forename: Anna
authors.initials: A
authors.lastname: Arroyo-Plasencia
authors.forename: Adam
authors.initials: A
authors.lastname: Stenger
authors.forename: Nick
authors.initials: N
authors.lastname: Krehbiel
authors.forename: Michael E
authors.initials: ME
authors.lastname: Mullins
mesh_terms: D000328:Adult; D004155:Diphenhydramine / Q000506:poisoning*; D062787:Drug Overdose; D005217:Fat Emulsions, Intravenous / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D012640:Seizures / Q000139:chemically induced* / Q000628:therapy; D013610:Tachycardia / Q000139:chemically induced* / Q000628:therapy
chemical_list: D005217:Fat Emulsions, Intravenous; D004155:Diphenhydramine